A. Field of Invention
This invention pertains to the art of biometric authentication and more specifically to a biometric system that uses a mobile device with a camera to capture a fingerprint image.
B. Description of the Related Art
U.S. Pat. Pub. No. 2012/0086794 discloses a contactless fingerprint acquisition and processing method that includes the steps of detecting and acquiring an object image, converting the object image into a fingerprint image and at least one of identifying and verifying the fingerprint image.
E.P.O. Pat. Pub. No. EP 2388734 discloses a photography subsystem configured to be operated in fingerprint scanning mode and a normal mode. An autofocus module may be initialized to control a lens with an initial focal length set according to received instructions indicating one of the modes of operation. An image signal processor associated with the photography subsystem may process images received from the photography subsystem and, if necessary, process the images to form a candidate digital fingerprint for use in an authentication process.
U.S. Pat. No. 5,828,773 discloses a fingerprint sensing device that includes a fingerprint sensor, a processor for determining an actual fingerprint position on the fingerprint sensor relative to a desired fingerprint position, and a finger position indicator for generating a finger position indication to assist the user in positioning the finger to the desired fingerprint position based upon the actual fingerprint position on the fingerprint sensor. The processor calculates a fingerprint center point defining the actual fingerprint position. The fingerprint sensor may be an electric field sensor in integrated circuit form. The finger position indicator may be a visual indicator, such as a position image indicia generator for generating image indicia on a display screen relating to the fingerprint position on the fingerprint sensor, and wherein an actual fingerprint position image is also generated relative to the position image indicia on the display screen. The position image indicia may be a desired fingerprint center point indicia image. Method steps of the design are also disclosed.
U.S. Pat. No. 8,312,291 discloses a biometric user authentication method that includes the steps of: enrolling a user based on user's biometric samples to generate user's reference data; and authenticating the user based on a user's live biometric sample and the user's reference data; wherein enrolling a user includes acquiring the user's biometric samples; extracting an enrollment feature vector from each user's biometric sample; computing a biometric reference template vector as a mean vector based on the enrollment feature vectors; computing a variation vector based on the enrollment feature vectors and the mean vector; randomly generating an enrollment secret vector; computing an enrollment code vector based on the enrollment secret vector and the variation vector; computing a difference vector as a wrap-around difference between the enrollment code vector and the mean vector; computing an error correction vector based on the enrollment secret vector to enable error correction during the user authentication phase according to a given error tolerance level, wherein the error correction vector is not computed if the error tolerance level is equal to zero; and storing the variation vector, the difference vector, and the error correction vector as a part of the user's reference data to be used during the user authentication phase.
U.S. Pat. Pub. No. 2008/0101664 discloses a method of recognizing 3D fingerprints by contact-less optical means. The method comprises inter alia the steps of: obtaining an optical contact-less means for capturing fingerprints, such that 3D optical images, selected from a group comprising minutia, forks, endings or any combination thereof are provided; obtaining a plurality of fingerprints wherein the images resolution of said fingerprints is not dependent on the distance between a camera and said inspected finger; correcting the obtained images by mis-focal and blurring restoring; obtaining a plurality of images, preferably 6 to 9 images, in the enrolment phase, under various views and angles; systematically improving the quality of the field depth of said images and the intensity per pixel; and, disengaging higher resolution from memory consumption, such that no additional optical sensor is required.